Traumatic Brain Injury Outcomes After Recreational Cannabis Use

pubmed logo

“Purpose: Basic science data indicate potential neuroprotective effects of cannabinoids in traumatic brain injury (TBI). We aimed to evaluate the effects of pre-TBI recreational cannabis use on TBI outcomes.

Patients and methods: We used i2b2 (a scalable informatics framework; to identify all patients presenting with acute TBI between 1/1/2014 and 12/31/2016, then conducted a double-abstraction medical chart review to compile basic demographic, urine drug screen (UDS), Glasgow Coma Scale (GCS), and available outcomes data (mortality, modified Rankin Scale (mRS), duration of stay, disposition (home, skilled nursing facility, inpatient rehabilitation, other)) at discharge and at specific time points thereafter. We conducted multivariable nested ordinal and logistic regression analyses to estimate associations between cannabis use, other UDS results, demographic factors, and selected outcomes.

Results: i2b2 identified 6396 patients who acutely presented to our emergency room with TBI. Of those, 3729 received UDS, with 22.2% of them testing positive for cannabis. Mortality was similar in patients who tested positive vs negative for cannabis (3.9% vs 4.8%; p = 0.3) despite more severe GCS on admission in the cannabis positive group (p = 0.045). Several discharge outcome measures favored the cannabis positive group who had a higher rate of discharge home vs other care settings (p < 0.001), lower discharge mRS (p < 0.001), and shorter duration of hospital stay (p < 0.001) than the UDS negative group. Multivariable analyses confirmed mostly independent associations between positive cannabis screen and these post-TBI short- and long-term outcomes.

Conclusion: This study adds evidence about the potentially neuroprotective effects of recreational cannabis for short- and long-term post-TBI outcomes. These results need to be confirmed via prospective data collections.”

“Available basic science and limited clinical data indicate potential neuroprotective effects of cannabinoids in traumatic brain injury (TBI). In this large retrospective study, we show that recreational cannabis use prior to TBI may confer neuroprotective short- and long-term benefits.”

Cannabidiol alleviates neurological deficits after traumatic brain injury by improving intracranial lymphatic drainage

pubmed logo

“Traumatic brain injury (TBI)-a severe clinical problem-is compounded by a lack of effective treatments and impeded intracranial metabolic waste clearance. The glymphatic system and meningeal lymphatic vessels are instrumental in TBI pathophysiology and crucial for clearing harmful substances.

Cannabidiol (CBD) has the potential to address metabolic imbalances and improve cognitive functions in neurodegenerative diseases, but its specific effect on TBI remains unclear. Using a fluid percussion injury model, we adopted a comprehensive approach that included behavioral testing, various imaging techniques, and deep cervical lymph node (dCLN) ligation to evaluate CBD’s effects on neurological outcomes and lymphatic clearance in a TBI mouse model.

Our results demonstrated that CBD markedly enhanced motor, memory, and cognitive functions, correlating with reduced levels of detrimental neural proteins. CBD also expedited the removal of intracranial tracers, increased cerebral blood flow, and improved tracer migration from lymphatic vessels to dCLNs. Intriguingly, CBD treatment modified aquaporin-4 polarization and diminished neuroinflammatory indicators. A key observation was that disrupting efferent lymphatic channels nullified CBD’s positive effects on waste removal and cognitive enhancements, whereas its anti-inflammatory benefits continued.

This finding suggests that CBD’s ability to improve waste clearance may operate via the lymphatic system, thereby improving neurological outcomes in TBI patients. Therefore, our study underscores CBD’s potential therapeutic role in TBI management.”

Cannabidiol reduces intraventricular hemorrhage brain damage, preserving myelination and preventing blood brain barrier dysfunction in immature rats

pubmed logo

“Intraventricular hemorrhage (IVH) is an important cause of long-term disability in extremely preterm infants, with no current treatment.

This study assessed the potential neuroprotective effects of cannabidiol (CBD) in an IVH model using immature rats.

CBD prevented the long-lasting motor and cognitive consequences of IVH, reduced brain damage in the short- and long-term, protected oligodendroglial cells preserving adequate myelination and maintained BBB integrity.

The protective effects of CBD were associated with the modulation of inflammation, excitotoxicity and oxidative stress.

In conclusion, in immature rats, CBD reduced IVH-induced brain damage and its short- and long-term consequences, showing robust and pleiotropic neuroprotective effects.

CBD is a potential candidate to ameliorate IVH-induced immature brain damage.”

“Cannabidiol (CBD), the main non-euphoric component of Cannabis sativa, has demonstrated neuroprotective effects in different models of acute diffuse or mild to moderate focal hypoxic-ischemic brain damage in newborn animals with a brain developmental stage similar to that of term human newborns.”

An Emerging Strategy for Neuroinflammation Treatment: Combined Cannabidiol and Angiotensin Receptor Blockers Treatments Effectively Inhibit Glial Nitric Oxide Release

pubmed logo

“Cannabidiol (CBD), the major non-psychoactive phytocannabinoid found in cannabis, has anti-neuroinflammatory properties.

Despite the increasing use of CBD, little is known about its effect in combination with other substances. Combination therapy has been gaining attention recently, aiming to produce more efficient effects. Angiotensin II activates the angiotensin 1 receptor and regulates neuroinflammation and cognition. Angiotensin receptor 1 blockers (ARBs) were shown to be neuroprotective and prevent cognitive decline. The present study aimed to elucidate the combined role of CBD and ARBs in the modulation of lipopolysaccharide (LPS)-induced glial inflammation. While LPS significantly enhanced nitric oxide synthesis vs. the control, telmisartan and CBD, when administered alone, attenuated this effect by 60% and 36%, respectively. Exposure of LPS-stimulated cells to both compounds resulted in the 95% inhibition of glial nitric oxide release (additive effect). A synergistic inhibitory effect on nitric oxide release was observed when cells were co-treated with losartan (5 μM) and CBD (5 μM) (by 80%) compared to exposure to each compound alone (by 22% and 26%, respectively). Telmisartan and CBD given alone increased TNFα levels by 60% and 40%, respectively. CBD and telmisartan, when given together, attenuated the LPS-induced increase in TNFα levels without statistical significance. LPS-induced IL-17 release was attenuated by CBD with or without telmisartan (by 75%) or telmisartan alone (by 60%). LPS-induced Interferon-γ release was attenuated by 80% when telmisartan was administered in the absence or presence of CBD. Anti-inflammatory effects were recorded when CBD was combined with the known anti-inflammatory agent dimethyl fumarate (DMF)/monomethyl fumarate (MMF). A synergistic inhibitory effect of CBD and MMF on glial release of nitric oxide (by 77%) was observed compared to cells exposed to MMF (by 35%) or CBD (by 12%) alone. Overall, this study highlights the potential of new combinations of CBD (5 μM) with losartan (5 μM) or MMF (1 μM) to synergistically attenuate glial NO synthesis. Additive effects on NO production were observed when telmisartan (5 μM) and CBD (5 μM) were administered together to glial cells.”

The modulatory role of cannabis use in subconcussive neural injury

pubmed logo

“Cannabis use has become popular among athletes, many of whom are exposed to repetitive subconcussive head impacts. We aimed to test whether chronic cannabis use would be neuroprotective or exacerbating against acute subconcussive head impacts. This trial included 43 adult soccer players (Cannabis group using cannabis at least once a week for the past 6 months, n = 24; non-cannabis control group, n = 19). Twenty soccer headings, induced by our controlled heading model, significantly impaired ocular-motor function, but the degrees of impairments were less in the cannabis group compared to controls. The control group significantly increased its serum S100B level after heading, whereas no change was observed in the cannabis group. There was no group difference in serum neurofilament light levels at any time point. Our data suggest that chronic cannabis use may be associated with an enhancement of oculomotor functional resiliency and suppression of the neuroinflammatory response following 20 soccer headings.”

“Our data show that chronic cannabis use may be associated with an enhancement of oculomotor functional resiliency and suppression of the neuroinflammatory response following soccer heading.”

Cannabinoids in traumatic brain injury and related neuropathologies: preclinical and clinical research on endogenous, plant-derived, and synthetic compounds

Journal of Neuroinflammation | Scholars Portal Journals

“Traumatic brain injury is common, and often results in debilitating consequences. Even mild traumatic brain injury leaves approximately 20% of patients with symptoms that persist for months. Despite great clinical need there are currently no approved pharmaceutical interventions that improve outcomes after traumatic brain injury. Increased understanding of the endocannabinoid system in health and disease has accompanied growing evidence for therapeutic benefits of Cannabis sativa. This has driven research of Cannabis’ active chemical constituents (phytocannabinoids), alongside endogenous and synthetic counterparts, collectively known as cannabinoids. Also of therapeutic interest are other Cannabis constituents, such as terpenes. Cannabinoids interact with neurons, microglia, and astrocytes, and exert anti-inflammatory and neuroprotective effects which are highly desirable for the management of traumatic brain injury. In this review, we comprehensively appraised the relevant scientific literature, where major and minor phytocannabinoids, terpenes, synthetic cannabinoids, and endogenous cannabinoids were assessed in TBI, or other neurological conditions with pathology and symptomology relevant to TBI, as well as recent studies in preclinical TBI models and clinical TBI populations.”

“Diseases with complex, multifaceted pathology, such as TBI, may require treatment that is multi-mechanistic, such as whole plant cannabis extracts.”

Cannabidiol’s neuroprotective properties and potential treatment of traumatic brain injuries

Frontiers - Crunchbase Company Profile & Funding

“Cannabidiol (CBD) has numerous pharmacological targets that initiate anti-inflammatory, antioxidative, and antiepileptic properties. These neuroprotective benefits have generated interest in CBD’s therapeutic potential against the secondary injury cascade from traumatic brain injury (TBI).

There are currently no effective broad treatment strategies for combating the damaging mechanisms that follow the primary injury and lead to lasting neurological consequences or death. However, CBD’s effects on different neurotransmitter systems, the blood brain barrier, oxidative stress mechanisms, and the inflammatory response provides mechanistic support for CBD’s clinical utility in TBI.

This review describes the cascades of damage caused by TBI and CBD’s neuroprotective mechanisms to counter them. We also present challenges in the clinical treatment of TBI and discuss important future clinical research directions for integrating CBD in treatment protocols.

The mechanistic evidence provided by pre-clinical research shows great potential for CBD as a much-needed improvement in the clinical treatment of TBI. Upcoming clinical trials sponsored by major professional sport leagues are the first attempts to test the efficacy of CBD in head injury treatment protocols and highlight the need for further clinical research.”

“There is strong mechanistic support that CBD could be an effective pharmacological intervention for TBIs, however the current state of the research field is mostly derived from rodent studies. The upcoming clinical trials will be especially informative for determining CBD’s efficacy as a TBI treatment.”

Cannabidiol for the Treatment of Brain Disorders: Therapeutic Potential and Routes of Administration


“The use of cannabidiol (CBD) for treating brain disorders has gained increasing interest. While the mechanism of action of CBD in these conditions is still under investigation, CBD has been shown to affect numerous different drug targets in the brain that are involved in brain disorders. Here we review the preclinical and clinical evidence on the potential therapeutic use of CBD in treating various brain disorders. Moreover, we also examine various drug delivery approaches that have been applied to CBD. Due to the slow absorption and low bioavailability with the current oral CBD therapy, more efficient routes of administration to bypass hepatic metabolism, particularly pulmonary delivery, should be considered. Comparison of pharmacokinetic studies of different delivery routes highlight the advantages of intranasal and inhalation drug delivery over other routes of administration (oral, injection, sublingual, buccal, and transdermal) for treating brain disorders. These two routes of delivery, being non-invasive and able to achieve fast absorption and increase bioavailability, are attracting increasing interest for CBD applications, with more research and development expected in the near future.”

Regulation of Expression of Cannabinoid CB 2 and Serotonin 5HT 1A Receptor Complexes by Cannabinoids in Animal Models of Hypoxia and in Oxygen/Glucose-Deprived Neurons


“Background: Cannabidiol (CBD) is a phytocannabinoid with potential in one of the most prevalent syndromes occurring at birth, the hypoxia of the neonate. CBD targets a variety of proteins, cannabinoid CB2 and serotonin 5HT1A receptors included. These two receptors may interact to form heteromers (CB2-5HT1A-Hets) that are also a target of CBD. 

Aims: We aimed to assess whether the expression and function of CB2-5HT1A-Hets is affected by CBD in animal models of hypoxia of the neonate and in glucose- and oxygen-deprived neurons. 

Methods: We developed a quantitation of signal transduction events in a heterologous system and in glucose/oxygen-deprived neurons. The expression of receptors was assessed by immuno-cyto and -histochemistry and, also, by using the only existing technique to visualize CB2-5HT1A-Hets fixed cultured cells and tissue sections (in situ proximity ligation PLA assay). 

Results: CBD and cannabigerol, which were used for comparative purposes, affected the structure of the heteromer, but in a qualitatively different way; CBD but not CBG increased the affinity of the CB2 and 5HT1A receptor-receptor interaction. Both cannabinoids regulated the effects of CB2 and 5HT1A receptor agonists. CBD was able to revert the upregulation of heteromers occurring when neurons were deprived of oxygen and glucose. CBD significantly reduced the increased expression of the CB2-5HT1A-Het in glucose/oxygen-deprived neurons. Importantly, in brain sections of a hypoxia/ischemia animal model, administration of CBD led to a significant reduction in the expression of CB2-5HT1A-Hets. 

Conclusions: Benefits of CBD in the hypoxia of the neonate are mediated by acting on CB2-5HT1A-Hets and by reducing the aberrant expression of the receptor-receptor complex in hypoxic-ischemic conditions. These results reinforce the potential of CBD for the therapy of the hypoxia of the neonate.”

Cannabidiol Reduces Short- and Long-Term High Glutamate Release after Severe Traumatic Brain Injury and Improves Functional Recovery


“This study aimed to determine if orally administered cannabidiol (CBD) lessens the cortical over-release of glutamate induced by a severe traumatic brain injury (TBI) and facilitates functional recovery. The short-term experiment focused on identifying the optimal oral pretreatment of CBD. Male Wistar rats were pretreated with oral administration of CBD (50, 100, or 200 mg/kg) daily for 7 days. Then, extracellular glutamate concentration was estimated by cortical microdialysis before and immediately after a severe TBI. The long-term experiment focused on evaluating the effect of the optimal treatment of CBD (pre- vs. pre- and post-TBI) 30 days after trauma. Sensorimotor function, body weight, and mortality rate were evaluated. In the short term, TBI induced a high release of glutamate (738% ± 173%; p < 0.001 vs. basal).

Oral pretreatment with CBD at all doses tested reduced glutamate concentration but with higher potency at when animals received 100 mg/kg (222 ± 33%, p < 0.01 vs. TBI), an effect associated with a lower mortality rate (22%, p < 0.001 vs. TBI). In the long-term experiment, the TBI group showed a high glutamate concentration (149% p < 0.01 vs. SHAM). In contrast, animals receiving the optimal treatment of CBD (pre- and pre/post-TBI) showed glutamate concentrations like the SHAM group (p > 0.05). This effect was associated with high sensorimotor function improvement. CBD pretreatment, but not pre-/post-treatment, induced a higher body weight gain (39% ± 2.7%, p < 0.01 vs. TBI) and lower mortality rate (22%, p < 0.01 vs. TBI).

These results support that orally administered CBD reduces short- and long-term TBI-induced excitotoxicity and facilitated functional recovery. Indeed, pretreatment with CBD was sufficient to lessen the adverse sequelae of TBI.”

“CBD administration decreases short- and long-term glutamate over-release after severe TBI, an effect associated with improvement of sensorimotor activity and body weight gain, as well as lower mortality. Future studies are essential to elucidate the mechanisms via which CBD exerts these effects and whether other mechanisms, such as antiinflammation, antioxidative stress, and neuroprotection, are involved. Our study suggests a neuroprotective effect of CBD short- and long-term after a severe TBI. These findings support orally administered CBD as a therapeutic strategy to prevent long-term consequences after TBI in the high-risk population, such as military personnel and contact sport athletes. It will also be interesting to determine if CBD neuroprotection is sufficient to prevent the development of long-term disorders following TBI, such as Alzheimer’s disease, Parkinson’s disease, and post-traumatic epilepsy.”